The present invention relates to an on-vehicle remote controller for controlling on-vehicle devices such as a door lock based on communication with a portable device.
Conventionally, various types of remote control devices are used, and a system known as a keyless entry system is widely used for releasing the door lock of a vehicle. With the keyless entry system, by operating on a portable device, an electric wave signal is transmitted from the portable device, which is then received at a vehicle-side receiver. Then, if an ID included in the received signal matches with an ID stored at the vehicle, the vehicle judges that the operation on the portable device is a proper operation and the door lock is released.
However, in this system, a user must take out and operate on the portable device. To avoid this operation, a smart entry system has been proposed. In the smart entry system, an ID request signal is transmitted from the vehicle and the portable device transmits an ID when it receives the ID request signal. In this manner, the door lock can be released without any operation on the portable device by the user.
The ID request signal can be transmitted from the vehicle in a number of ways, including a method for transmitting the ID request signal when a user operates a door outer handle and a method for transmitting the ID request signals constantly, with a predetermined interval in between, when the user is away from the vehicle. The method for transmitting an ID request signal when the door outer handle is operated has an advantage that the battery consumption can be reduced, but can result in a delay in releasing the door lock, and thus, the method of constantly transmitting ID request signals with a predetermined interval in between is preferred.
In the system for periodically transmitting an ID request signal as described above, there are cases where interference occurs and sufficient communication cannot be obtained. For example, if a plurality of portable devices approach a vehicle, a plurality of IDs are simultaneously transmitted from the portable devices, resulting in the vehicle being incapable of receiving the ID, and remote operation cannot be performed even when one of the portable devices is the proper portable device. Moreover, when two vehicles are close together, ID requests are transmitted from both vehicles. In this case, when an ID request is transmitted from a second vehicle, the portable device is in the process of responding to the ID request transmitted from the first vehicle, and thus, is unable to respond to the ID request from the second vehicle. If the second vehicle is the vehicle corresponding to the portable device, because the portable device always responds to a vehicle which transmits the ID request signal first, the portable device does not respond to the second vehicle, and the vehicle corresponding to the portable device cannot be remotely operated.
A system for transmitting an ID request signal when the door outer handle is operated is described in, for example, U.S. Pat. No. 5,552,641. Specifically, the ""641 patent describes coding the ID request signal and transmitting the coded signal, but this coding is not for preventing an interference from a plurality of vehicles. Moreover, if the ID request signal is coded by a complicated coding method, circuits for coding and decoding for this purpose must be provided, resulting in a complicated and/or expensive device.
One object of the present invention is to provide an on-vehicle remote operation control device which can reliably remote operate an on-vehicle device even when a plurality of vehicles and/or portable devices exist in an area.
Another object of the present invention is to effectively prevent remote operation by fraudulent communication.
According to one aspect of the present invention, there is provided an on-vehicle device remote controller for mounting on a vehicle and for controlling a predetermined on-vehicle device based on communication with a portable device, the remote controller comprising: an ID request signal transmitting device for intermittently transmitting an ID request signal to a portable device in a predetermined interval; ID receiving means for receiving an ID signal from the portable device; checking means for checking the ID received by the ID receiving means with a predetermined proper ID; and device operation control means for operating the predetermined on-vehicle device when the checking is successful at the checking means; wherein the transmission of ID request signal is controlled to be inhibited when the checking has failed at the checking means.
When one portable device receives ID request signals from two vehicles, it responds to the first received ID request signal. If the portable device is not the device corresponding to the vehicle to which the device responded, ID checking fails. In this case, the vehicle where the ID checking failed is controlled to inhibit the generation of ID request signals. In this manner, the portable device can respond to an ID request signal from the second vehicle and can remotely operate on the second vehicle. Moreover, because the ID request signal is inhibited, the device can discourage attempts at fraudulent communication.
It is preferable that the checking means include comparison means for comparing the received ID and the proper ID from the beginning of the received ID while the ID is being received by the ID receiving means.
The ID from the portable device is transmitted as a response to the ID request signal from the vehicle. Therefore, the vehicle knows the beginning of the received ID and can compare it with the stored ID bit-by-bit while the ID is being received. When a difference is detected, the communication can be terminated at that point, thus reducing the electric wave traffic and the power consumption.
A failure of checking at the checking means is preferably detected after at least a few failures are detected in the received ID. Because one detection of difference may be due to a burst error, if transmission of ID request signal is inhibited immediately after one failure detection, an unnecessary delay tends to occur. By inhibiting the transmission of the ID request signals based on a plurality of differences detected, such an erroneous decision can be prevented.
It is preferable for the ID request signal transmitting means to increase the transmitting level of the ID request signal when a predetermined manual operation is performed by a user after transmission of the ID request signal is inhibited.
When the door outer handle is operated or when a wireless code is transmitted from a portable device, it is obvious that the user will operate on the vehicle, and reliable communication can be performed in such cases by increasing the transmitting level of the electric wave.
The inhibition of the transmission of the ID request signal is preferably performed by decreasing the transmission level of the ID request signal, so that the portable device can receive other ID request signals. By suspending transmission of the ID request signals, attempts at fraudulent communication can be restricted.
It is preferable to inhibit transmission of the ID request signal by elongating the period between the intermittently transmitting ID request signals. By changing the length of the period between transmissions, collision of the electric waves can be easily and reliably avoided.
According to another aspect of the present invention, there is provided an on-vehicle device remote controller mounted on a vehicle for controlling operation of a predetermined on-vehicle device based on communication with a portable device, the controller comprising: ID request signal transmitting means for intermittently transmitting ID request signals to a portable device at a predetermined interval; ID receiving means for receiving an ID signal from the portable device; checking means for checking the ID received by the ID receiving means with a predetermined proper ID; and device operation control means for operating a predetermined on-vehicle device when checking is successful at the checking means; wherein the transmitting interval of the ID request signal at the checking means can be sequentially changed in a predetermined manner.
By changing the transmitting interval of the ID request signal, continuous collisions between the ID request signals from a plurality of vehicles can be effectively prevented.
It is also preferable to change the transmitting interval of the ID request signals from the checking means every time an ID request signal is transmitted.
It is preferable that the ID request signal transmitting means transmits a car number assigned to each vehicle and further transmits an ID request signal when a response to the car number and the checking means confirms checking of the proper ID by determining that a response code in the response from the portable device generated for the challenge code is generated in a predetermined manner based on the challenge code.
In this manner, communication specifying the key for the vehicle can be performed, and by using a challenge code, communication which is difficult to crack can be performed.
It is also preferable that the checking means confirms checking by determining a fixed code for specifying a preregistered portable device is included in the response from the portable device for the challenge code.
The portable device can be specified by the fixed code and can be confirmed. Moreover, the control of the on-vehicle device itself can be changed using the portable device.
It is also preferable that the checking means detects a condition where the fixed code from the portable device is proper but the response code is not, and that the checking means determines failure of checking after a plurality of such conditions are detected.
In this manner, attempts at fraudulent communication can reliably be detected.
It is also preferable that the on-vehicle device controller further comprises display means for displaying the checking failure when the checking has failed.